The following relates generally to devices which decrease the possibility of jackknifing in tractor trailer rigs and provides information for improved steering control. More particularly, the following reflects continuing developments over my U.S. Pat. No. 4,341,395 issued July 27, 1982.
The problems and difficulties associated with tractor trailers jackknifing are well documented and need not be belabored here. Suffice to say, loss of property, personal injuries and the like can be averted by having a device on tractor trailers which would reduce the possibility of jackknifing while simultaneously not impairing the ability of the driver to steer and control the rig.
In the earlier patent, a system was provided which allowed first and second pins to be extended upwardly on lateral extremities of the fifth wheel device to alter the range of motion of the vehicle.
The instant invention is distinguished over the earlier patent and those patents of record at that time (which are incorporated herein by reference) in that a fifth wheel has been provided which includes a slot transverse to the longitudinal axis of the truck and integrally formed with the fifth wheel forward thereof. Below the slot, a pin is carried within a housing on the tractor adapted to be extended without the housing and its slot and placed within a trailer slot so as to provide a constraint should the tractor angulate relative to the trailer beyond the dimension of the trailer slot.
More particularly, a means for preventing jackknifing and enhancing driver control is disclosed hereinafter in which a forward anchor plate portion of the fifth wheel is provided with a slot and allows communication with a housing mounted on a stationary portion of the tractor adjacent the fifth wheel below the slot, the housing including a locking pin capable of extension adapted to pass through the anchor plate slot, the trailor above the anchor plate also having a slot provided thereon. The trailer slot is adapted to receive the locking pin therein for limiting the motion of the fifth wheel of the tractor trailer relative to each other to avoid jackknifing and enhance control. A specific linkage is included for elevating the locking pin which includes first and second bars adapted to rotate in an arcuate path by expansion and contraction of an interconnecting cylinder so as to elevate the locking bar from within the recess of the housing to an upwardly extending position so as to engage the slot of the trailer. Limit switches are associated with axles providing motion to the locking pin so that the range of motion of the tractor trailer can be controlled by the locking pin through these limit switches. A control device is strategically oriented in the driver's cab to allow manual actuation of the device and an indicator is provided to indicate the status of the locking pin during various modes of driving.